JP4238515B2 - Stirring method in methane fermentation water tank and water tank for breeding aquatic organisms such as methane bacteria - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method and an apparatus for stirring a liquid filled in a container such as a water tank, and a water tank for aquatic organisms equipped with the same.
[0002]
[Prior art]
Conventionally, for stirring in the methane fermentation water tank, an air pump is used to circulate compressed biological gas from the lower part of the water tank through a diffuser, so-called gas stirring method, mechanical stirring with a stirring blade, pump In addition, there is a method of circulating the liquid in the methane fermentation tank. Both require power costs for stirring.
[0003]
[Problems to be solved by the invention]
This invention is made | formed in view of such a point, and provides the stirring tank in the methane fermentation tank which does not require the power cost for stirring, and the water tank for breeding aquatic organisms, such as a methane bacterium.
[0004]
[Means for solving problems]
1stly, it is the method of stirring the liquid in methane fermentation tank w using the biological gas produced | generated by methane fermentation, Comprising: It is provided in the liquid of methane fermentation tank w in methane fermentation tank w substantially vertically. A gas phase part g is formed around the lower part of the outflow pipe p by a partition wall, an outer wall surface of the outflow pipe p, and a water surface below the partition wall, and a biological gas is sent into the gas phase part g to attach to the liquid solid. Utilizing the adhesion force and surface tension, the biological gas is intermittently and suddenly overflowed into the outflow pipe p from the lower end of the outflow pipe p, and a gas layer is formed in the outflow pipe p. Biological gas and liquid are ejected from the upper end of the pipe p, thereby stirring the inside of the methane fermentation tank w, and the biological gas sent into the gas phase part g is introduced into the gas phase part g from the liquid below the gas phase part g. In the methane fermentation tank, which is a biogas that emerges It is a 拌方 method,
Second, it is installed in a prismatic or cylindrical methane fermenter w, and the liquid filled in the methane fermenter w is stirred using gas.
(C) An upper sealed container c having a liquid inflow port i and having a gas phase part g for containing a gas above the inside thereof.
(D) An outlet pipe that opens below the upper partition in the upper sealed container c and above the inlet i, extends substantially vertically upward through the upper partition, and opens below the liquid level of the water tank w. p
A stirrer comprising a methane fermentation tank for raising methane bacteria using organic waste as a nutrient source, purifying the wastewater, and collecting methane gas, It is a water tank for breeding aquatic organisms such as methane bacteria.
[0005]
[Example and operation]
Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of the apparatus of the present invention. A stirrer b is fixedly installed in a methane fermentation tank w for culturing and growing acid-producing bacteria such as acetic acid bacteria and methane bacteria using organic wastewater as a nutrient source, purifying the wastewater, and collecting methane. . A wastewater inlet, a treatment liquid outlet, a desulfurizer, a biological gas storage tank, and the like are also provided, but not shown. The stirrer b includes an upper sealed container c, an outflow pipe p, and an inflow port i. The outflow pipe p penetrates the upper partition 2 of the upper sealed container c, opens substantially horizontally below the upper partition 2 and is provided substantially vertically. The upper end of the outflow pipe p is configured to open below the liquid level s2. The inflow port i is provided at a portion located below the outflow pipe lower opening 3 of the side wall 4. A gas phase portion g is formed by the upper partition wall 2, the side wall 4, and the outflow pipe p outer wall surface.
Next, the operation will be described. When the biological gas generated by methane bacteria (dotted arrow) that slowly rises from below in the upper sealed container c flows continuously into the gas phase part g, the liquid level s1 descends and reaches the lower end of the outflow pipe p. The liquid is further lowered by the action of adhesion force and surface tension to the solid. Eventually, when the action of the adhesion force and surface tension on the liquid solid reaches the limit, the biological gas in the gas phase part g flows into the outflow pipe p from the periphery of the lower part 3 of the outflow pipe p at once. A gas layer is formed in the outflow pipe p while pushing up the water inside. At the same time, a liquid corresponding to the gas flowing into the outflow pipe p flows into the upper sealed container c from the inflow port i. Immediately, the gas layer pushes up most of the liquid above the gas layer in the outflow pipe p and lifts the liquid below the gas layer in the outflow pipe p, and rises in the outflow pipe p. It spouts vigorously.
After the liquid level s1 has risen slightly, it begins to descend again, and when the action of the adhesion force and surface tension of the liquid again reaches the limit, the gas in the gas phase part g is discharged from the periphery of the lower opening 3 of the outflow pipe p. It flows into the outflow pipe p at once, pushes up the water in the outflow pipe p, and forms a gas layer in the outflow pipe p. At the same time, a liquid corresponding to the gas flowing into the outflow pipe p flows into the upper sealed container c from the inflow port i. Immediately, the gas layer pushes up most of the liquid above the gas layer in the outflow pipe p and lifts the liquid below the gas layer in the outflow pipe p, and rises in the outflow pipe p. It spouts vigorously. Thereafter, this ejection is repeated periodically. The liquid in the water tank w flows and is agitated by the ejection of the liquid into the upper closed container c accompanying the ejection and the ejection.
The intensity of stirring by one ejection is determined by the ratio of the gas-liquid contact area in the upper closed container c to the cross-sectional area of the outflow pipe p, the cross-sectional area of the outflow pipe p, and the length of the outflow pipe p. As the ratio of the gas-liquid contact area in the upper closed container c to the cross-sectional area of the outflow pipe p increases, the height of the gas layer formed in the outflow pipe p increases and the rising speed increases. Vigorous drawing of the liquid into the upper closed container c occurs, and the stirring force increases. Further, as the cross-sectional area of the outflow pipe p and the length of the outflow pipe p are increased, a large amount of liquid is ejected and a large amount of liquid is drawn into the upper sealed container c, and the stirring force increases. The ratio of the gas-liquid contact area in the upper sealed container c to the cross-sectional area of the outflow pipe p is appropriately about 50 or more.
The apparatus of the present invention accumulates the continuously flowing biological gas and discharges it at a stroke. Therefore, even if the inflow speed of the gas is slight, the number of ejections is reduced, but a certain large ejection occurs. Thus, in this invention, it can stir only with the biological gas which methane bacteria generate | occur | produce from the downward direction in the upper airtight container c, and the motive power expense for stirring becomes unnecessary. Moreover, since the liquid in a tank only passes through a thick pipe, there is no clogging.
The cross section of the lower end 3 of the outflow pipe p is substantially horizontal. Thereby, air flows in uniformly into the outflow pipe p, and an air layer is effectively formed. This levelness is particularly required when the diameter of the outflow pipe p is large.
The inflow port i is not limited to four places as shown in the figure. It is desirable to provide it at a plurality of locations and allow the water tank w to flow evenly.
In addition, since the apparatus of the present invention has no mechanical part that comes into contact with the liquid, there is no concern about corrosion, and maintenance can be easily and inexpensively performed.
[0006]
【The invention's effect】
As described above, the apparatus of the present invention utilizes the action of the adhesion force and surface tension of a liquid to the solid and the levitation force of the gas, and stores the biological gas generated by methane bacteria or the like in the gas phase portion g. It is characterized in that a large amount of liquid is ejected by overflowing into the outflow pipe p at once.
The advantages of the present invention are summarized as follows.
(1) With a simple structure, non-powered stirring can be performed. No stirring power cost is required.
(2) A large stirring force can be obtained only with the generated biological gas.
(3) A constant stirring force can be obtained regardless of the gas generation speed. Even if the gas generation rate is low, stirring is not disabled.
(4) Since there are no mechanical or moving parts in contact with the liquid, there are few failures and maintenance can be made inexpensive.
According to the method and apparatus of the present invention as described above, methane fermentation treatment of organic waste can be performed at low cost.
[0007]
[Brief description of the drawings]
FIG. 1 is an explanatory view of a longitudinal section showing an embodiment of the apparatus of the present invention.
[Explanation of symbols]
c is an upper closed vessel, g is a gas phase portion, i is an inlet, p is an outlet tube, s1 and s2 are liquid surfaces, w is a methane fermentation tank, 2 is an upper partition wall of the upper closed vessel c, and 3 is an outlet tube p 4 is a side partition of the upper closed container c.
Solid arrows indicate the direction of liquid flow. Dotted arrows indicate the direction of biogas flow.

Claims (3)

This is a method of stirring the liquid in the methane fermentation tank w using the biological gas produced by methane fermentation, and is an outflow pipe provided substantially vertically in the liquid of the methane fermentation tank w in the methane fermentation tank w. A gas phase part g is formed around the lower part of p by a partition wall, an outer wall of the outflow pipe p, and a water surface below the partition wall, a biological gas is sent into the gas phase part g, and the adhesion force and surface tension of the liquid to the solid Is used to intermittently and rapidly overflow the biological gas from the lower end of the outflow pipe p into the outflow pipe p to form a gas layer in the outflow pipe p. The biogas and liquid are ejected, thereby stirring the inside of the methane fermentation tank w, and the biogas sent into the gas phase portion g floats in the gas phase portion g from the liquid below the gas phase portion g. Stirring method in methane fermentation tank characterized by being biogas Installed in a prismatic or cylindrical methane fermenter w, and stirs the liquid filled in the methane fermenter w using gas,
(A) An upper sealed container c having a liquid inflow port i and having a gas phase part g for storing gas in the upper part of the inside thereof.
(A) An outflow pipe that opens below the upper partition in the upper sealed container c and above the inflow port i, penetrates the upper partition, extends substantially vertically upward, and opens below the liquid level of the water tank w. p
A stirrer comprising a methane fermentation tank for raising methane bacteria using organic waste as a nutrient source, purifying the wastewater, and collecting methane gas, A water tank for aquatic organisms such as methane bacteria equipped with a stirring device. The water tank for breeding aquatic organisms such as methane bacteria according to claim 2, wherein the lower end of the outflow pipe p is substantially horizontal.

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